Noncorrosive soluble oil containing active sulfur



Patented Oct. 13, 1953 UNITED PATENT OFFICE Z ni 55,478

NONCORROSIVESOLUBDE OIL CONTAINING- ACTIVE SULFUR Alien 3-; fieutser; Northville; Mich, and Fred '1". Crooksh'aiik', Port-Arthur, Tex, assigno'rs to The -'lexas;-qoinpany, New York, N;- Y.,- a cor' porationlof -nelawafe No Drawing. Original application June 25", 1949, g riatric, 101,4 88 now lfatent' No. 2,626,240, dated Jaiiiiary go; 1953. Divided and this ap=- pliOafimTMfifcli-l, 1952, Serial N; 274,494

12 Claims:

This -invention=relates= anemmsmahe-mom cant-comprising anunerailubrieating oil which disperses readily-in.thepresencegor water; and more particularly wifi'solliblifii forfiise as a cooling and lubricating fliiid' 'iii-inetal working :operations; such asthe-outtifig; grinding and turning of metals".-

This is adivisidii-oi fiiif eofifidiiigapplieation Serial No. 101,488, filed June 25, 1'949;-iiow U. S; Patent No. 2,626,240, dated Janna-r910," I953;

With the use of 'lligher machiiie speefis ineutting and grindirig operationsg and the desire to take larger 01 deeper'euts; the operations fi =quently become toosevere to be handled satis factorily by the conventional type OFSOlllbl Oil :acter. In orderto obtain the required extreme gpressu're pro erties; ititems l'ieeirfound desirable :to employ a sulfurized mineral-lubricating oil-eon taming loosely combined activesulfuras opposed to the use of sulfurized fatty-oil's or fats-sulfurized under high heat and/oppressive providingtightly bound or comb'ined'sulfur; The produetlon of mineral lubricatingoils con'taining about 015' to 4.0% of loosely combined-active sulfur iswell known as illustrated bytneKaufmanU; s; Pat'- eht No. 2,167,439; wherein the mineraiiubri'cating oil is heated with the-required proportion of free sulfur in the absence (if-a:fattyfoilfand'at at mospheric' pressure at-"a -controlled temperature of about 300360 Fl for a period'of time-of about 1-4 hours to fix the sulfur in the :oil in *a=1oose1y bound active f'oifli. While tnistype otsulfun zed mineral lubricating oil is preferredg itlls-to" be understood that" mineral murioatine oils sulfurizedunder high heatco'nditioiis; 'o'r suliurized in the presence of a small proportion of fattyoil, can also b used for purposes of the present invention provided the mineral oil containssome loosely combined or active sulfur; Thus the mineral lubricating oils may or may not contain tightly bound sulfur inaddition to a contentof ilbOS'ly combined oractive Offlt least about *55 0375- 33 of 'free sulfurand the mixture heated 6.25% or higher; When asulfurized mineral oil containin'gacti've sulfur of this-type is employed as a proportion or'all of-the lubricating base of the Soluble oil; which is diluted with water at the time of use to provide emulsions containing from about "5" to ormore parts-ofwater to one of oil; the activesulrur' in the presence of water results in objectionable corrosion of ferrous metals or steel employed in-th work.

0ne of theprincipal objects'of the present invention is to provide an emulsifiable lubricant containing aotivesulfur' afiording extreme pressure properties-or increased 1 load carrying. capacity,'-and which at-th'e same timesis effectively'inhibited against" steel corrosion-in the presence of water;

Anotherobject of the-present invention is-to provide a-soluble-oilhaving'as a major constituent sulfurizedininei'al lubricating oil with loosely combined active sulfur, and which is substantially non corrosivew'ith respeet'to steel in th presence of-Water.

Another object of the present invention is to providean" improved method of compounding a soluble-oiiof 'thischaracter in order to produce a-soluble oil with superior extreme pressure properties in'an economical manner.

Qther objects-and advantages ofthe-invention will -=he-apparent-frorii the following description iih appended Claims.

Inaccordance with-the present invention,- a superior soluble oil 1 possessing extreme pressure properties is providedb'y'= mixing a sulfurized mineral lubricating-oil containingloosely combined active sulfur with an unsulfurized mineral lubricating oil solution of the soap or other emulsifying agent, saidso'lution containingasmall proportion of -water aSWlI as a -high b0iling organic liquid 'oouplin'g a ent or-n'iutu'al solvent, the two being mixed' insuch Proportions that the sulfurized-minera-l lubricatingoil is the major constituentof the composition and then inhibitm the soluble "oil aga'inst steel corrosion in the presence orwaner by 'adding a small amount in viscosity 'or'degree -of refining, depending on the 4 grade-or viscosity of the ultimate-solubl oil desired. This oilis preferably mixed with about pletely saponified at about 300-340 F. for a period of about 1-4 hours to obtain a sulfurized mineral lubricating oil containing about 0.75-3.0% by weight of loosely combined active sulfur.

The emulsifier employed in the composition may comprise any of the conventional alkali metal or amine soaps or mixtures thereof customarily employed in soluble oils and capable of promoting the formation of an oil-in-water emulsion, such as natural or synthetic carboxylates, sulfonates, resinates and naphthenates. In addition, the various synthetic or non-soap emulsifiers which are well known in the detergent field, including the hexahydric alcohol partial esters of high molecular weight fatty acids and the anhydrides thereof, such as sorbitan monooleate, can also be employed for this purpose. either alone or in combination with a soap emulsifler. Preferably. a soap emulsifier is used which comprises a sodium mahogany sulfonate, which is a sodium soap of the oil-soluble sulfonic acids obtained in the sulfuric acid treating of petroleum hydrocarbons. A very satisfactory soap-emulsifier in accordance with the present invention comprises a mixture containing substantial proportions each of sodium mahogany sulfonate, sodium resinate and sodium naphthenate. A proportion of about -20% by weight of soap, or mixture of soaps, is ordinarily employed on the basis of the soluble oil composition and preferably about by weight.

The preferred soap base specified above is conveniently prepared by forming a solution in unsulfurized mineral lubricating oil, preferably a light oil having a Saybolt Universal viscosity at 100 F. of about 70-150 seconds of rosin, naphthenic acids and sodium sulfonate, and then saponifying this solution by heating with an aqueous caustic solution. It is pointed out that the mahogany sulfonic acids are conveniently recovered in purified form as a. solution of sodium mahogany sulfonate in non-saponifiable minral lubricating oil.

' As noted above, the sulfurized mineral lubricating oil is purposely not utilized as make-up oil to form the solution of the rosin, naphthenic acids and sodium sulfonate. It has been found that, when the rosin and/or naphthenic acids were saponified with the aqueous alkali or caustic soda solution in the presence of the sulfurized a mineral lubricating oil, there was an excessive consumption of the alkali, and at the same time a product was obtained which was difiicultly emulsifiable and had poor emulsion stability. Apparently the caustic soda reacts with the active sulfur of the sulfurized mineral lubricating oil, and"the formation of reaction products gives rise to the "'mulsification difficulties. Consequently, a sulfurized mineral lubricating oil is separately formed, and the soap base is com- Y in the absence of the sulfurized lubricating oil. It ispreferable to utilize about the minimum amount of unsulfurized mineral lubricating oil as will insure proper liquefaction of these constituents for the subsequent saponification; and for this purpose the amount of unsulfurized mineral lubricating oil is preferably adjusted to obtain an ultimate total soap content following saponification which is around 50% by weight. Ease .of handling is the only limitation to the soap content of the base, and a more concentrated or less concentrated soap base can be used, if desired. The required pro.- portion of the soap base is ultimately added to the sulfurized mineral lubricating oil to give the desired soap content in the finished soluble oil, and at the same time the sulfurized mineral lubricatingoil will constitute the major constituent of the soluble oil, generally about 60-70% thereof by weight, to provide high extreme pressure properties. It will be understood that where liquid emulsifiers are used, the addition of unsulfurized mineral lubricating oil to form the emulsifier base solution is not required; and the pro-- portion of sulfurized mineral lubricating oil in the soluble oil composition can thereby be further increased, such as up to about or some-- what higher. Also the preformed soaps can be compounded with the sulfurized mineral lubricating oil, thereby enabling the proportion of the latter in the ultimate soluble oil composition to be increased.

It is found desirable to have the ultimate soluble oil slightly on the acid side, and for this purpose, an excess of naphthenic acids is used to provide a neutralization number of about 1-3 in the soap base. Effective control is ordinarily and conveniently secured by addin additional free naphthenic acids over and above the amount required for production of the desired amount of naphthenate soap either prior to or following completion of the saponification reaction. Ordinarily, an amount up to about 0.8% by weight of free naphthenic acids will be present in the finished soluble oil.

. As is well known, soluble oils are usually prepared in the form of a concentrated emulsion or colloidal solution containing a minimum quantity of water to enable the oil, at the time of use, to rapidly take up additional quantities of water to form the dilute 5:1 to :1 emulsions customarily employed for the cooling and lubrication of the metal working operations. In order to form a concentrated soluble oil of this character which is stable in storage against separation of ingredients, a small proportion of the order of 0.4-1.0% Of a high boiling organic liquid coupling agent or mutual solvent is added to the soluble oil. Examples of very satisfactory coupling agents of this character are the monobutyl ethers of ethylene glycol and diethylene glycol, various alkylene glycols, and esters and ethers thereof. This coupling agent may be added to the soap base following saponification, or it can be added following the addition of the sulfurized mineral lubricating oil.

In addition, the water content of the concentrated soluble oil is also found rather critical for storage stability, and varies between about 1-4% by weight of the, soluble oil depending on the soap or emulsifiercontent and the amount of coupling agent employed. In order to effect saponification of the rosin and naphthenic acids and conveniently maintain the water content within the stable range, a rather concentrated caustic soda solution, such as one of 49 strength, is employed. Following saponification, additiona1 water may be added along with the organic liquid coupling agent to the soap base, or to themixture of soap base with sulfurized mineral lubricating oil, to adjust the water content within the most stable portion of the efiective range.

In accordance With the present invention, the soluble oil is rendered non-corrosive with respectto. ferrous metals such as steel by incorporating therein about 01-20% of an aliphatic alkylenepolyamine having from 3 to 20 carbon atoms in the molecule. By alkylene it will be understood that this refers to the source of the hydrocarbon group as being formed from an olefin, and not to assume 'dianiiiie's- {of tetramethylefie; pentamethylene; I

hexamethyrene, heptamethyierie; "octamethylerre, and rionametliiilenet addition, one or more hydrogen-atom or=- the polymethylenesnueleusof the foregoing ompou'nds: can: be substituted by amino. groups; as exem nfiedrby lieitaniethylene tetrammewneremtwmor ther-hydrogezratonie of the hexamethylene-nucleuein hexamethylenedi amine 'are substitutee bya amino groupsh In addition to the foregoing straight chain polymethylene polyamino compounds set: forth above, the branch chain: olefin polyaminotcom:- pounds: having' from 3 to 20 :carbon 'atoms in the molecule are also suitable for purposes of: the present invention Examples of: this"; type in- -cludepropylene dlanune, butylene diamine, pentyl'ene diamine, heia'ylene dla'mine; octylene dlami'rie such 'as oiisobiitylenet diamine; triism butylenediamine *andz tetraisobutylene diamine. Moreover, one onmore ofi the hydrogen; atoms or the branch earbomohainaortheioreg oing:compounds can be substitutedlbytafiiilio groupsisnch as propylene triamine, butyleneetetramine; and the like.

Another very satisfastory 'subwgroup; of; compounds nfalling within this-iclasssrof' effective com- 4 pounds for purposes: oittheipresenteinvention are those termed. herein: aliphatic polyolefin polya-minesfhavingt 4 1:020 carbon atoms in-zthe ED1016- cule and which aincludez 'anwNHhgroupmrgroups within the carbon: chain imadditioni-to the terminalNH groups; Thesearesformed bya=condensation reaction as-exemplified by the condensationof' twat-molecules; of -ethylenerdiamine producing; diethylenetriamine,

Hm C Cm-6 C Nfii n with the sp itting. ofrerfmn. Further condensation produces ltiithylefie. 'ttramme, tetraeth'ylene pentamine, 'pentaetlwlene he'xamine,

etc. whichare also. highly effective for purposes.

of this invention. Siinilar' condensationproducts .of propylene diain'ine, lautylenediamine', etc.

can likewisebe. employed.

Moreover, any oftheforegoing compounds can be, further substitutedty replacing-a- Hydrogen.-

the aliphatic polyethylene -polya-mi nes' are preferred; and; of these, diethylenetriamine is-selected from the standpoint of cost:-

In addition, a bacteriostatie agent as-well as an odor-ant; both of conventionalcharacter,may "be added to the finished soluble aoileimproporrespectively; Any suitable bacteriostatlc agent 'lmowntor'control'or inhibit bacterial growth in solublev on; emulsions; such as: 2,3 A,6 tetra'chloro'- phenoL. and'anysuitable essential oil or other odorant whichz imparts a; pleasing. odor to the compositiommay' be: employed.

'The-composition-of the preferredtype of soluble' oil prepared accordance-with: the present irrvention maytallwithin: the following percentage: limitsrby: weight-based on the: solubleoil, with the preferredrange being also indicated:

- 1Percent= Preferred mgfemm a'geliir'iits" range 5 Sulfurlzed'mlnrallubridafingollwith rely combinod'activefsulfiirz. J.- 50 85 60 70 Unsuliurized mineral lubricatingmil -0 20-10- Water: 1 23 Bacteriostatic ag 0.44). s Odorant (optional) 0.-0i0. l

0 1% freetsiilfurltiyweig'lit'while' the'oil was-main- 0 sulfuriaed oiljare a's renews:-

taine'd at" a temperature of"300 310""F. with stirring, followed by hours (Jr-soaking. at" this temperature with continued stirring: Under these conditions; thesulfur'soaddetl was almost 5 eutireiydissolved or loos'e'l'y 'conibihed'f in an aetiifefdrmiittheofli 'softliat i't'would show u 'in a standard test ro r'reeisinfur as. distinguished combiner sulfur; Y "rest-s obtainedon the originalniniefallubricatingoil and-the resulting l *Lubrlaffi" Bulflir'iied Tests ingloil' oil oievit A-II;; me 9 Flash Cleyeland' Qpenvf] F r 405 :390 Fire Cleveland OperuCup, 31*: 455 447 vlscosltysa'ybolt univeisalat 10o 786 g isqos tyj Saybo1t Universal at" 210 seer. 58v 5 our Total sulfur-,- percent Free sulfur, percent 1.-2

. The soap base for thfiS'rSUlllblB oilbatch-w'as prepared. as follows: Bi l-pounds of a-lubricatin'g oil solution of sodium. mahogany sulionate analyzing32.8% by. weight of sodium sulfonate. the balancebeing non-saponifiable mineral lub'ricati ng oil, were toa compounding kettle. Gum rosin havingasaponification number of 170 was then ohargedto the kettle in-the amount of 196 pounds; .iollowing which 337 pounds of naphthenic acids we're-added; the latter having a saponification value of 99 and .non saponifiablecontent of '3'1Z4=%' by weight consistingesseniiially' of mineral lubricating oil. In

addition, dfi poiiiids of a light naphthene base minerallubricating oiliwere addedfas based on calculations to bring the ultimate soap content. following y'saponification to. around" 50% by weight. The added mineral lubricating oil had the following testes The steamwas turned on to the kettle and the stirrers started, with heating being continued for about V hour until the kettle contents had been raised to a temperature of 245-260 F. and the added rosin had dissolved. The steam was then turned off and cooling water turned on to the kettle jacket to cool the contents to about 175 F. when a 49 caustic soda solution was charged to the kettle in the amount of 92 pounds for saponification. This required approximately an hour at a temperature of 175-150 F.

Samples of the resulting lubricating oil solution of mixed sulfonate, resinate and naphthenate soap were withdrawn for tests to determine the required amount of naphthenic acids to be added to adjust the neutralization number of the batch to around 2.0, as well as to determine the required amount of additional water needed to adjust the water content of the completed soluble oil to about 2.3%. For this purpose, 13.7 pounds of the above-described naphthenic acids and a total of 82.5 pounds of additional water were required. In the procedure followed in this particular batch, the naphthenic acids were first added to adjust the neutralization number. Then 2,836 pounds of the above described sulfurized mineral lubricating oil were stirred into the mix wihile maintained at a temperature of about 220-150 F., and 36 pounds of water were added as the batch cooled. In order to complete the preparation, 25.5 pounds of ethylene glycol monobutyl ether were added when the batch had cooled to about 110 F.; and finally at substantially room temperature 46.5 pounds of water together with 8.5 pounds of diethylene triamine were stirred in, the final addition of water being required to adjust the water content to the desired figure and compensate for some evaporation which had taken place.

The resulting soluble oil 'had a green color with a musky ammoniacal amine odor. The composition of the finished soluble oil in percent by weight was:

Sulfurized lubricating oil 66.5

Unsulfurized lubricating oil including nonsaponiflable oil from the added sodium sulfonate and naphthenic acids". 14.9

Tests obtained on this particular batch of soluble oil were as follows:

Color, Lovibond cell--- 840. Viscosity Saybolt Universal at 100 F., sec 2787 Stability of water emulsions Completely stable in all proportions. Color of emulsion Greenish white.

Low temperature stability- No separation.

Tests on SAE load tester at 500 R. P. M.

Water-oil ratio emulsion strength:

011 only 1bs 5,500+ 2-1 lbs 2,030 5-1 lbs 1,760 -1 "lbs" 1,700 20-1 lbs 1,710 50-1 lbS 1,700

Corrosion test The SAE test of the foregoing table was carried out with the standard SAE. load tester utilized for determining the extreme pressure properties'of lubricants, except modified as follows: A small storage tank containing the soluble oil or soluble oil emulsion under test was mounted about 3 feet above the Timken cups of the SAE machine. A /8" pipe connected to the tank served to deliver the emulsion to the test cups through a suitable valve. The discharge end of the pipe was fitted with a piece of ,4 copper tubing flattened at the discharge end to form a slit opening, which served as a nozzle to deliver a flat stream of the emulsion to the cups. The end of the nozzle was arranged approximately one inch from the line of contact or the Timken cups and the stream of emulsion was directed so that it would strike the top cup just above the line of contact. In this manner, a. stream of the fresh test lubricant was fed to the test cups during the entire period of the run, and simulated the normal procedure for applying soluble oil emulsion in the case of metal machining or grinding. The foregoing test shows the soluble oil to possess extreme pressure properties even in dilute emulsion form. It will be appreciated, in accordance with the standard SAE test, that the higher the rating number, the better is the extreme pressure property of the lubricant; and that the soluble oil alone rated above the test limit of the SAE machine.

The corrosion test of the foregoing table is a measure of the corrosiveness of the soluble oil or soluble oil emulsion to ferrous metals, such as steel. In the case of the soluble oil alone, the test was carried out by placing a metal strip, approximately 3 inches long and A; inch wide in a tall form 4 oz. bottle, with about A; of the strip covered with the oil to be tested. The bottle was then tightly stoppered and allowed to stand vertically at a temperature of 5 F. for a period of 168 hours, following which the metal strip was removed from the bottle and washed with water. The specimen was then examined visually for evidence of discoloration, etching and pitting. Only a slight discoloration is allowable and no pitting or etching should be present. The test on the emulsion of the soluble oil was carried out in the same manner, except that the metal strip was completely covered with the emulsion under test. The foregoing tests show that the soluble oil and the water emulsions prepared therefrom were non-corrosive with respect to the low carbon steel specimen.

Other tests carried out on the said soluble oil showed it to have satisfactory hard water stability and ease of emulsification, and to be satisfactory in anti-rust properties.

While the foregoing soluble oil containing a small amount of diethylene triamine was satisfactorily non-corrosive, this soluble oil in the absence of such an effective inhibitor is obj ectionably corrosive to ferrous metals such as steel. Moreover, it was found by extended tests that corrosion inhibitors previously employed in conjunction with sulfur containing additives in lubricating oils proved entirely ineffective in this new environment of a soluble oil involving the presence of substantial amounts of water. In these tests, the aliphatic alkylene polyamines aeeeeve mmerse-least: 3.. carbon atoms-in the moleeule asoeiinee above were ioune universally en. e: tive non eorr sives new ro ient... is the'iollowingtable. which sets-iorth. the results. of. the ahQ e. -des ri.b d e02:

rosioniteso on samnles oi the said soluble. oil or BEEF.

. oven Gene. l m l- Inhibitor in 51011 Ap'peeronee of steel strip nil strength 1:10 eer" Foiled e s 1 Do. lit-1 7 I ss bl ny ark beeke on p- -9 ee 3 flq ele ely overed by a th s. Week o ;9 5 4 Black,

5 L .7 Q. BE]- 1 Y y thi b ack o .5 5.-1 7 0. K. J5, t-l 'i 2 Ye -M1181 b c c t. .11 e; Ki =1. 0 5-1 1 a sli htly discolored.

2- ee ree. 3;- .--2w 0:1 1 .2 Do- .2 2M 1 2 'Govoied with a soft tum blockcan. i2 H; 1 f .Do. "2 5: 3i, 0- K- Her 19 in hespecific. example e. hih tor wasemn oyeeor else aeifierent hi nor was subsiituterl in .the ind. .a.. ed Per. iib wei ht f rihe methylene .triaheine of one vn ei ie xa ple. While-thestamlard cor osion t t ge scribed above employeda time Qt .7 fil maternperatur oi 1.29 .1? oersainofihe So ls shown in the table. were .01 fine -tent nota ion and o: other t mperatures. as ini catecleorro'sion tests oi he f regoing ta le we made in; h samema ner as es bes. abo e for he soluble oil emul ion. .In a di o om o the Samples wh ch had. be n xposed or th inid foo ed he 1 oftime @12 F- were hen sluhl'eeterl in fur he e posure at 16 v1 0;- the shown. i 1 order to p o de mo e ri orous he res ts o the t b e how that a re= portion of at least about 0.1% by weight f the TABLE "f I Days in oven gin-.1. mmbmr E ppeomn e e ste s r p I 1310. In 1.5

5-1 2 Heavy black flaked corrosion. v g, 51-; I7 I lossibly a few dark specks0. K. .12. 5-; e 0. K.

I2 5-1 4 W M 9.1;. .52 5 1 7 O. K.

5-1 3 but a spots.

'ilre foregoing table sets forth by way of example members o: .o iierene subgrou s of effecti e elipha e alk ene nolyam nes co tain ins at Least 3 car on atoms the molecule of the present-invention. .In ad on, the table illusizroise the nsatis act ry resu ts obt ined with oertein representative yp s ,oi eorro lon bitors as previously employed in {giggggl lubr cate in oil in other relat onships W ile an alipha i lsvlene polyem n sueh y e diami e, has heretofore been suggested as a color inhibitor for a lubricating oil of the type of a motor oil or turbine 011 when used in proportions substantially less than 0.1% by weight, it was not to be anticipated that these higher molecular weight alkylene olyamines would function in a substantially higher proportion range for the new purpose or inhibiting corrosion of steel in the presenee. o water in h ne e vi onme t r an. emu

sitlable lubricant containing active sulfur, The results are all the more unexpected since COI- roslon inhibitors previously employed in other relationships proved entirely inefiective in this new environment,

slie h iene es ti l to rd P ope proee ion a ai s ste l ee s -v or h tomary service with the more concentrated emulsions propor o of ar und 0.2% and by weight eshe ti ely appears su ei nt a fiheue higher pr portions up to about l+ may b em n o ed. where mo ri or us ondition a e neou te esl- By way off .fur her exam le. the ol o in i l ted as represen a of a sol l 1 p epare .aee rdanee with the pr s n nv n ion and which has proved very satisfactory in service:

Per cent by weight Sulfurized mineral lubricating oil containing about 1% by weight of loosely com- Diethylene eriamine-fi .b Wa r Per cent by weight 2,3,4,6-tetrachlorophenol .6 Blend of essential oils known as Fritzsche Compound No. 08219, manufactured by Fritzsche Bros. Co .025

The addition of the essential oil blend as an odorant, and of the 2,3,4,6-tetrachlorophenol as a bactericide improve the product by masking the ammoniacal musky odor of the inhibitor, and serving to prevent the formation of emulsion odors by bacterial action. In the formula set forth above utilizing the 2.4% water content, it was found advisable to incorporate the 2,3,45- tetrachlorophenol in the soap base and adjust the neutralization number to about 2.0 prior to the addition of the sulfurized lubricating oil. However, the bactericide can be added to the finished soluble oil, in which case it is desirable to increase the water, content by approximately 1% from that shown for added stability. The first method is preferred since, as a general proposition, soluble oils of higher water content are less satisfactory from a storage stability standpoint than those of lower water content.

While the present invention has been particularly described above as applied to a so-called soluble oil, it is to be understood that the invention is more generally applicable to an emulsifiable lubricant containing loosely combined or active sulfur, together with an oil-in-water emul-' sifier, and wherein it is desired or required that the lubricant be non-corrosive to ferrous metal in the presence of water.

Obviously many modifications and variations of the invention as above set forth may be made without departing from the spirit and scope thereof, and therefore only such limitations should be imposed as are indicated in the appended claims.

We claim:

1. An emulsifiable lubricant which is essentially non-corrosive to steel in the presence of water, comprising as the major constituent a Sulfurized mineral lubricating oil containing loosely combined active sulfur, an alkali metal soap emulsifier, and about 01-20% by weight based on the lubricant of an aliphatic C1-C3 alkylene polyamine having from 3 to 20 carbon atoms in the molecule effective to inhibit said lubricant against steel corrosion in the presence of water.

2. An emulsifiable lubricant according to claim 1, wherein the said polyamine is an aliphatic polyethylene polyamine.

3. A soluble oil comprising as the major constituent sulfurized mineral lubricating oil containing loosely combined active sulfur, an emulsifying agent capable of promoting the formation of an oil-in-water emulsion, water, a high boiling organic liquid coupling agent, and about 01-20% by weight based on the soluble oil of an aliphatic C1-C3 alkylene polyamine having from 3 to 20 carbon atoms in the molecule efiective to inhibit said lubricant against steel corrosion in the presence of water.

4. A soluble oil according to claim 3, wherein the sulfurized mineral lubricating oil contains about 0.7 5-3.0 by weight of loosely combined active sulfur and is present in a proportion of about 50-85% by weight based on the soluble oil.

5. A soluble oil according to claim 4, wherein the said polyamine is an aliphatic polyethylene polyamine; 1

6. A soluble oil comprising as the major constituent sulfurized mineral lubricating oil containing loosely combined active sulfur, soap emulsifier inculding alkali metal mahogany sulfonate, water, a high boiling organic liquid coupling agent, and about 0.1-2.0% by weight based on the soluble oil of an aliphatic polyethylene polyamine having from 4 to 20 carbon atoms in the molecule efiective to inhibit said soluble 011 against steel corrosion.

7. A soluble oil according to claim 6, wherein the soap emulsifier consists of sodium mahogany sulfonate, sodium resinate and sodium naphthenate.

8. A soluble oil according to claim 7, containing a small amount of free naphthenic acids.

9. A soluble oil according to claim 8, wherein the aliphatic polyethylene polyamine is diethylene triamine.

10. A soluble oil consisting essentially of the following constituents in per cent by weight based On the soluble oil:

Sulfurized mineral lubricating oil containing 0.75-3.0% by weight of loosely combined active sulfur 60-70 Unsulfurizedmineral lubricating oil 20-10 Sodium mahogany sulfonate 4-6 Sodium resinate 4.5-5.5 Sodium naphthenate 4.5-5.5 Free naphthenic acids 0.2-0.6 High boiling organic liquid coupling agent- 0.5-0.8 Aliphatic polyethylene polyamine 0.l-1.0 Water 1-4 Bacteriostatic agent 0.4-0.8 Odorant 001-01 '11. A soluble oil consisting essentially of the following constituents in the approximate percentages by weight based on the soluble oil:

Sulfurized mineral lubricating oil containing about OHS-3.0% by weight of 12. An emulsifiable lubricant which is essentially non-corrosive to steel in the presence of water, comprising as the major constituent a sulfurized mineral lubricating oil containing loosely combined active sulfur, an alkali metal soap emulsifier, and about 0.1-2.0% by weight of diethylene triamine.

ALTON J. DEUTSER. FRED T. CROOKSHANK.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,929,955 Nelson Oct. 10. 1933 2,062,652 Herrmann et al. Dec. 1, 1936 2,211,250 Anderson et a1 Aug. 13, 1940 2,231,214 Nelson et a1 Feb. 11, 1941 2,268,608 McNulty et al Jan. 6, 1942 2,296,037 Kaufman Sept. 15, 1942 2,328,727 Langer Sept. '7, 1943 2,358,581 Lieber et a1 Sept. 19, 1944 2,892,891 Wallace et al. Jan. 15, 1946 

1. AN EMULSIFIABLE LUBRICANT WHICH IS ESSENTIALLY NON-CORROSIVE TO STEEL IN THE PRESENCE OF WATER, COMPRISING AS THE MAJOR CONSTITUENT A SULFURIZED MINERAL LUBRICATING OIL CONTAINING LOOSELY COMBINED ACTIVE SULFUR, AN ALKALI METAL SOAP EMULSIFIER, AND ABOUT 0.1-2.0% BY WEIGHT BASED ON THE LUBRICANT OF AN ALIPHATIC C1-C3 ALKYLENE POLYAMINE HAVING FROM 3 TO 20 CARBON ATOMS IN THE MOLECULE EFFECTIVE TO INHIBIT SAID LUBRICANT AGAINST STEEL CORROSION IN THE PRESENCE OF WATER. 